Digestion process

Question 1

What is digestion?

Why is digestion necessary?

Answer 1

1)Breakdown of large insoluble food molecules into small soluble molecules.

2)Large molecules are too big to be absorbed, so they must be broken down.

Question 2

What does amylase do?

What does maltase do?

Answer 2

1)Breaks starch → maltose (mouth & pancreas).

2)Breaks maltose → glucose (small intestine).

Question 3

What do proteases do?

What is the role of pepsin?

Answer 3

1) Break proteins → amino acids.

2)Protease in stomach; works in acidic pH (~2).

Question 4

What is the role of trypsin?

What do lipases do?

Answer 4

1)Protease in small intestine; works in alkaline pH (~8).

2)Break lipids → fatty acids + glycerol.

Question 5

What is the role of hydrochloric acid in the stomach?

Answer 5

Kills bacteria and provides acidic pH for enzymes.

Question 6

What is the role of bile?

Answer 6

Neutralises stomach acid and emulsifies fats (increases surface area).

Question 7

How is the ileum adapted for absorption?

Answer 7

Villi + microvilli → large surface area
Thin walls → short diffusion distance
Good blood supply → rapid transport
Lacteals → absorb fats

Question 8

What is the hepatic portal vein?

Answer 8

Carries nutrient-rich blood from intestine to liver.

Question 9

What are the functions of the liver?

Answer 9

Processes nutrients, regulates blood glucose, detoxifies substances.